1. Field of the Invention
The present invention relates to quick-set clamping mechanisms, and in particular, to an improved vise assembly which allows a user to initially to preset the jaws by sliding them together in one quick motion to save time, followed by conventional fine-screw-adjustment for clamping.
2. Description of the Background
The bench vice is an age-old tool for clamping and holding a work piece. A conventional bench vise, as shown in FIG. 1, includes a sliding jaw 12 mounted on a screw-spindle that is turned by a handle 10. The other end of the screw-spindle is pivotally anchored in a housing 18 that sits on a base 16. A stationary jaw 14 is integrally attached to the housing 18. Manually turning handle 10 moves the sliding jaw 12 toward or away from housing 18, respectively clamping or unclamping a workpiece. Although the utility and convenience of the traditional bench vise is beyond question, there is ample room for improvement. For example, if a user works on a large workpiece followed by a small one, he or she must adjust the jaws of the vice by screw-action from a wide-open position to a substantially closed one. This requires a great deal of turning effort and time.
It would be far more convenient to provide a quick-set mechanism to allow rapid opening and/or closing of the gap between the jaws. For example, when the gap between the jaws is at its largest and the user wants to clamp a small workpiece, it would be helpful to have the ability to slide the jaws together in one quick motion and thereby eliminate the need for a long hand cranking operation on the screw-spindle. On the other hand, a quick-setting adjustment capability as described would still need to work in conjunction with a conventional screw-clamping mechanism to give the user a reduction drive to exert a sufficient clamping force on the work piece without causing the two clamping mechanisms to bind up.
There have been a few prior efforts to develop clamping mechanisms that slide together. For example, U.S. Pat. No. 6,093,361 to Schad shows a clamp system in which a clamp piston 30 engages a rack 36 for reciprocating movement of a platen. Clamp piston 30 has teeth 34 that engage corresponding teeth 36 on column 24. Rotation of clamp piston serves to engage or disengage clamp piston teeth 34 from column teeth 36. However, this particular clamp design was intended for an injection molding machine, and the design is specifically adapted for this purpose.
It would be greatly advantageous to provide an improved clamping mechanism in the context of a bench vise which allows a user to rapidly open and/or close the gap between the jaws. This would allow the user to initially preset the jaws by sliding them together in one quick motion to save time, followed by conventional fine-screw-adjustment for reduction clamping.
It is, therefore, the primary object of the present invention to provide an improved quick-set clamping mechanism which allows a user to initially to preset the jaws by sliding them together in one quick motion, followed by conventional fine-screw-adjustment for high-force clamping.
It is another object to provide a vise with dual-adjustment mechanism which enables the jaws to be moved rapidly and in a single motion together, and which allows a separate clamping arrangement for moving the vise members relatively together a smaller distance to forcefully clamp the workpiece between the two jaws.
This object is achieved by providing a dual-action quick-set clamping mechanism, herein described in the context of a bench vise. The clamping mechanism includes a stationary jaw portion having a channel there through, and a toothed rack lining the channel. In addition, a slidable jaw portion includes a protruding hollow three-walled (top and two opposing side walls) beam that is inserted into the chamber of the stationary portion. A mandril having a threaded end is rotatably mounted within the hollow beam of the slidable portion. In addition, a toothed pawl having a threaded through-bore is mounted on the threaded end of the mandril. Thus, the mandril and pawl sit in the hollow of the beam of the slideable portion within the channel of said stationary jaw portion. The pawl has a bias spring for biasing the teeth of the pawl into engagement with the teeth of the rack. However, a user may quickly open or close the slidable jaw portion relative to the stationary portion by disengaging the pawl from the rack and sliding the beam of the slidable portion into (or out of) the channel of the stationary portion. Alternatively, the user may engage the pawl with the rack for screw-closing (or like opening) of the slidable portion against the stationary portion in a conventional bench-vise-like manner. This provides a quick-set clamping mechanism which allows a user to initially to preset the jaws by sliding them together in one quick motion, followed by conventional fine-screw-adjustment for high-force clamping.